Any other recommendations for mods that will improve my enjoyment of what is supposed to be one of the best FPS-RPGs ever made would be greatly appreciated.

I'd consider the ReBirth mod equally essential. It replaces most of the character models in the game with more detailed versions and more high res textures. Does a lot to improve the atmosphere in the game even further, in my opinion.

It's a bit tricky to install properly though so make sure you follow the instructions carefully. Otherwise you might end up with all the characters in the game being invisible, I noticed.